Technical Field
The invention relates to a method for controlling a water sluice gate drive for a water sluice gate, in particular for a roller sluice gate, preferably in a hydroelectric power plant, wherein the drive has an asynchronous machine, in particular an asynchronous motor/generator. In addition, the invention relates to a service connection for controlling a water sluice gate drive for a water sluice gate. In addition, the invention relates to a water sluice gate drive and a hydroelectric power plant.
Description of the Related Art
A hydroelectric power plant is used to convert potential energy in water into electrical energy. In so doing, dammed up or running water in a water collection is fed in the direction of the current via a debris catcher and an inlet grill to a turbine, which is typically disposed in a turbine pipe, (e.g., suction pipe or pressure pipe), and said water thereby drives the turbine. The water leaving the turbine is fed to the further water outlet via an outlet. Depending on the drop height between the water collection and the outlet, a distinction is made between low, middle and high-pressure hydroelectric power plants; here, a drop height may regularly lie in the range between 1 m and up to 10 m, and in some cases even above 15 m. Depending on the drop height, different types of turbines may be used, as is described in EP 1 440 240 B1, for example. Independent of the concrete design of a turbine, it has been shown that these turbines should be operated depending on the load; for example, a load-dependent operation of a turbine can be achieved by means of a variably adjustable turbine geometry, for example by modifying the pitch angle of turbine blades. It may also be necessary to recognize an emergency closure situation and, in so doing, to close a water sluice gate, which has been provided for the protection of a hydroelectric power plant; this may be the case, for example, with a fully open turbine geometry, including during normal operational or test situations; e.g., in the case of turbine blades that have been pitched out of the current (turbine on a channel way). This may also apply to real emergency situations; for example in the case of the intrusion of debris that may have an adverse effect on a turbine, or if water discharge must be stopped in the event of technical problems in the hydroelectric machine and/or turbine of a hydroelectric power plant. In the present case, an emergency closure situation is understood to mean any operating situation in which it is necessary or useful to close the water sluice gate in front of the turbine or in front of the turbine pipe of the turbine respectively.
In the present case, a water sluice gate is generally understood to be a part of a weir system, in particular in a hydroelectric power plant, which has a movable protection device, in particular a vertical sluice gate, to control the water flowing though the weir system, in particular in a hydroelectric power plant. A vertical sluice gate may be guided in the recesses of weir posts for example, which posts are anchored in the weir system. As a rule, a distinction is made between a sliding sluice gate and a roller sluice gate, depending on whether the vertical sluice gate can be moved in guide rails and/or is guided with the aid of guide rollers such as the running and guide rollers of a roller arrangement. A water sluice gate drive is generally understood to be any drive that is suitable for setting the vertical sluice gate in motion or to inhibit such motion, possibly in combination with a gear unit, either directly or by means of a roller arrangement such as running and guide rollers.
In an operating situation, in particular an emergency closure situation, what is problematic on the one hand is that a protection device such as a vertical sluice gate having a comparatively high weight force must be swiftly set in motion. While a weight force of the vertical sluice gate is at first basically advantageous in initiating the movement, on the other hand, the considerable power of resistance generated by the weight force must be overcome in order to move a vertical sluice gate. The power of resistance is especially attributable to the frictional force that acts on the guide of the vertical sluice gate, in particular also as a result of the hydrodynamic power. Vertical sluice gates may have weight forces of possibly several tons up to the double-digit ton range.
On the one hand, a vertical sluice gate or similar protection device may have to be moved against inertial forces and especially frictional forces, possibly in the shortest possible time, in an operating situation such as an emergency closure situation in order to prevent damage, in particular in the worst case to prevent the destruction of the turbine system and/or the hydroelectric machine (in particular comprising a generator or similar electric hydroelectric machine, in particular comprising some kind of gearing mechanism or similar drive train components and/or current-forming components) of the hydroelectric power plant.
Above all, movement of a vertical sluice gate and the control of a water sluice gate drive upstream therefrom is especially critical when the emergency closure situation coincides with a situation in which a power supply is no longer available for the water sluice gate drive; this situation proves to be especially problematic in the event that an electric machine, thus an electric motor/generator, is provided in the water sluice gate drive. This is because in the above mentioned emergency closure situation without a power supply, the conventional measures for braking the electric machine in the water sluice gate drive are only conditionally available as a result of the absent power supply.
In such a situation, it would be expected that a vertical sluice gate of a water sluice gate that is being freely brought down during an emergency closure situation would cause massive damage to the guide of the vertical sluice gate at the point at which it impacts the ground; this would be due to the inertial forces of an impacting vertical sluice gate having a high weight. For example, the forces of a 30 ton vertical sluice gate with a drop height of 10 m could result in the destruction of at least the guide and the bottom of the water sluice gate as well as possibly the vertical sluice gate itself. In particular, the jamming of the aforementioned vertical sluice gate in the guide may be the undesired result.
As a result, not only must a rapid movement of the vertical sluice gate in an emergency closure situation be ensured in the event of an absent power supply, but in addition, an appropriate control of the water sluice gate drive must be ensured in order to prevent the vertical sluice gate from striking the ground unhindered.
The German Patent and Trademark Office has researched the following prior art in the priority application for this application: DE 80 09 242 111 U1 and DE 893 920.